Thanks for the additional context.  I don't really think there are any material concerns for data security.  Integration is definitely a draw.  There are those of us who are not really big on data import though, which works well when it does but could be a pain when it doesn't.  You may like to set up a mock client or two and test out the functionalities for yourself first hand as a client, if you have not already done so.  There are pros and cons to Intuit Link but there has not been a lack of complaints from tax pros and clients.